Permease

permease

[′pər·mē‚ās]

(biochemistry)

Any of a group of enzymes which mediate the phenomenon of active transport.

Permease

 

a component, probably of a protein nature, of certain biological membranes that transports metabolites across the membrane. Each permease transports a specific group of chemically similar compounds, and its biosynthesis is controlled by a single gene. The most extensively studied permeases have been those that transport carbohydrates in bacteria, although permeases for amino acids and several ions are also known. The bacterium Escherichia coli has from 30 to 60 different permeases.

The term “permease” is often extended to imply a functional meaning, that is, to designate an entire multicomponent system for the transport of a certain compound. This usage is erroneous, since permeases cannot be equated with enzymes, which are also named by adding the suffix “-ase.” It has been proposed that permeases be called transport proteins, or transfors.

REFERENCES

De Robertis, E., W. Nowinski, and F. Saez. Biologiia kletki. Moscow, 1973. (Translated from English.)
Cohen, G. N., and J. Monod. “Bacterial Permeases.” Bacteriological Reviews, 1957, vol. 21, no. 3, p. 169.

V. K. ANTONOV